Cleaning a Foam Cushion

I have a cloth sofa with removable covers. I had a toddler over that had a potty accident on the sofa. I have removed the cover and cleaned it but it think the foam cushion is damaged also. My question is, how do I clean the foam or can I replace it at a reasonable price?

You could also try sprinkling the cushion with bicarbonate of soda (baking soda). Leave for half an hour and vacuum. I did this on a carpet where one of my cats did a Number Two and it worked beautifully; no smell and stains afterwards.

I have found foam tha can be cut to your sizes needed at Jo-Ann's fabrics..(and no I don't work at one..I've purchased one there) and then if it is too big and needs a little trimming..use electric knife to cut..works like a charm....hope this helps,deb